William o



Patented May 9, I899.

ANNUNG IATOB FDR TELEPHONE SWITGHBOARDS.

a E N s\ w E M 0 w (Application filed Nov. 17, 1898.)

(No Model.)

- Will/10111111111111! ms u'cams PETERs co.. vnoTqumofl wnsumnromwifnegses: gwm

WILLIAM O. MEISSNER, OF CHICAGO, ILLINOIS,

BURNS, OF SAME PLACE.

NlTE STATES PATENT E- ASSIGNOR TO PETER c.

ANNUNCIATOR FOR TELEPHONE-SWITCHBOARDSJ SPECIFICATION forming part ofLetters Patent No. 624,838, dated May 9, 1899.

Application filed November 17, 1898. Serial No. 696,693. (No model.) i

T at whom 112% may concern:

Be it known that I,W1LLIAM O. MEISSNER,

a citizen of the United States of America, and

a resident of Chicago, Cook county, Illinois, have invented a certainnew and useful Improvement in Annunciators for Telephone-Switchboards,of which the following is a specification.

At the central office of a a switchboard is provided, by means of whichoperators are enabled to establish connections closing theelectromagnet.

between the various lines of the subscribers for the purpose ofconversation. It is necessary at such switchboards to provide meanswhereby the attention of the operator may be directed to any line by anyone or more of the subscribers. For this purpose what are termedannunciators are employed,1ocated upon the switchboard, one or more foreach subscribers line. These annunciators are operated by a current ofelectricity generated by means of an electric machine at eachsubscribers station. 7

My invention relates to certain improvements in the annunciators; anditconsists in certain features of construction and details of arrangementto be described, and pointed out in my claim, reference being now had tothe accompanying drawings, in Which- Figure 1 is a side elevation of myannunciator. Fig. 2 is a central longitudinalsection. Fig. 3 is a planView. Fig. 4 is a cross-section on the line 4 4 of Fig. 1. Fig. 5 is arear view.

My invention relates to certain improvements in that class ofannunciators of the tubular type which employ a magnetic sleeve in- Inthese so-called tubular drops the electromagnet operates an armaturepivoted Orhinged in the rear of the electromagnet and at the upper sidethereof, which extends from the rear to the front of the magnet andterminates in a latch,which is adapted tonormally engage and hold apivoted shutter located in front of the magnet. When a current ofelectricity is sent from a snbscribers station, it traverses the coilsof the electromagnet of the annunciator of such subscriber on theswitchboard,which magnet then attracts the armature and releases theshutter, which then falls, thereby giving a telephone system mally holdthe shutter K scriber desires connect-ion with some other line. 7 As myinvention relates only to improvements in this signal device, itisunnecessary to describe the further operations for connecting the twosubscribers together.

The object of my invention is to provide a drop or annunciator whichshall be more sensitive in operation, and therefore require a current ofless strength to energize the electromagnet and move thelatching-armature to release the shutter, and also to provide meanswhereby access maybe readily hadto the electromagnet and .itsconnectionsfor repair and the like.

Having reference now to the drawings previousl y described, it will beobserved that the electromagnet is designated at A, Fig. 2, disposedwithin the shell or sleeve B of magnetic material.

The armature D is pivoted at D to the curved supporting-arms E. Thearmature latch-arm H is secured to and extended from the upper portionof the armature D and at a point remote from the pivot D of saidarmature. Said latch-arm H extends forward beyond the face-plate J andhas formed therewith a latch H adapted to engage and nor in a verticalrestored position.

The face-plate J is secured to and held by the arms E, which latter aresecured to the magnetic sleeve 13.

A guard or protectorL is provided, projected from the face-plate J, justabove the latch H a a and b 1). Access maybe conveniently ob- V tainedto the electromagnet by withdrawing the screws from the ears and thenpulling the electromagnet longitudinally out of the sleeve, as shown inFig. 3 by the dotted lines.

An insulating-block N is also secured to the face-plate J and holds thenight alarm-con- IOO tacts L A circuit common to all of the drops orannunciators is connected in turn to each of these sets of nightalarm-contacts and a common audible signal device is included in thecircuit. The night alarm-circuit is normally open at the annunciators;but when the drop-shutter falls the contacts are operated by the shutterto close the circuit to the signal device, which gives an audible alarmand serves in the night-time, when the number of operators in attendanceis reduced, to attract the attention of the operator.

It will be observed that the armature of the eleetromagnetis pivoted orhinged at its lower end or edge and is thereby held, so that it requiresbut little attractive influence or energy to move the armature, operatethe short arm of the latch, and release the shutter. The necessarymovements of the armature are also exceedingly minute and a sensitiveresponsive action obtained by a greatly-reduced current strength.

Having thus described my invention, what I claim as new therein, anddesire to secure by Letters Patent, is

In an annuneiator for telephone-switchboards the combination of thefollowing instrumentalities: a front plate or support, carrying apivoted shutter, a pair of supportingarms extending rearwardly from andattached to the front plate, a metal cylinder mounted on said arms, adetachable cover closing its rear end,.an electromagnet in saidcylinder, an armature between said cylinder and the front plate, saidarmature being pivoted at its lower extremity between thesupportingarms; a latch-arm extending forwardly from the upper extremityof said armature through the front plate to engage the shutter, and aninsulating-block lying between the supporting-arms and carryingcontact-springs to cooperate With the shutter, substantially asdescribed.

Signed by me, at Chicago, Cook county, Illinois, this 8th day ofNovember, 1898.

WILLIAM O. MEISSNER.

Witnesses:

CHAS. O. BULKLEY, L. M. BULKLEY.

